/Engine/Plugins/Runtime/MeshModelingToolset/Source/ModelingComponents/Public/Selection/GeometrySelector.h
Update the active transform (eg called on each mouse update during 3D gizmo usage). The caller provides a VertexTransformFunc callback, which will only be called during the call to UpdateTransform to compute new 3D positions for 3D points.
void UpdateTransform ( [TFunctionRef](API\Runtime\Core\GenericPlatform\TFunctionRef)< FVector3d(int [VertexID](API\Plugins\MeshModelingToolsExp\EMeshInspectorToolDrawIndexMode), const FVector3d &InitialPosition, const FTransform &WorldTransform)> VertexTransformFunc )